Raible L H, Gorzalka B B
Peptides. 1986 Jul-Aug;7(4):581-6. doi: 10.1016/0196-9781(86)90030-6.
The effects of 200 ng of intracerebroventricularly (ICV) and 20 micrograms of subcutaneously (SC) administered alpha-melanocyte stimulating hormone (MSH) on lordosis in rats were examined. Previous research, employing crossover designs, has revealed significant effects of MSH on lordosis. The results of Experiments 1a and 1b suggest that similar designs produce significant effects even in the absence of MSH. Thus, it is not clear that previous results were due exclusively to an action of MSH. Experiment 2 employed a modification of previous procedures and indicated that MSH administered either SC or ICV inhibited receptivity in subjects displaying high levels of responding. Moreover, MSH administered SC was also found to facilitate receptivity in subjects displaying low levels of responding. However, a possible long term inhibitory action of MSH on receptivity was also revealed. Because animals were tested repeatedly, this brought into question the results of Experiment 2. Procedures were revised accordingly and the effects of MSH re-examined. The results of Experiment 3 indicated that MSH administered SC facilitated receptivity while MSH administered ICV inhibited receptivity. In addition, MSH administered ICV exerted an inhibitory effect one week after administration. Therefore, MSH appears to exert both short and long-acting effects on sexual receptivity.
研究了脑室内（ICV）注射200纳克和皮下（SC）注射20微克α-黑素细胞刺激素（MSH）对大鼠脊柱前凸的影响。以往采用交叉设计的研究表明，MSH对脊柱前凸有显著影响。实验1a和1b的结果表明，即使在没有MSH的情况下，类似的设计也会产生显著影响。因此，尚不清楚先前的结果是否完全归因于MSH的作用。实验2对先前的程序进行了修改，结果表明，皮下或脑室内注射MSH会抑制反应水平较高的受试者的接受性。此外，还发现皮下注射MSH会促进反应水平较低的受试者的接受性。然而，也揭示了MSH对接受性可能存在的长期抑制作用。由于对动物进行了反复测试，这使得实验2的结果受到质疑。因此对程序进行了相应修改，并重新研究了MSH的作用。实验3的结果表明，皮下注射MSH会促进接受性，而脑室内注射MSH则会抑制接受性。此外，脑室内注射MSH在给药一周后仍有抑制作用。因此，MSH似乎对性接受性具有短期和长期作用。
